• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.298-302
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• 2022

South Korea has a temperate climate with four distinct seasons. However, summers are extremely hot and humid, which negatively affects industrial animal production. Hanwoo are native cattle that have traditionally been raised in the natural environment of Korea. The present study investigated the effects of birth and lactation season on the birth and weaning weights of Hanwoo calves. Data were collected from 100 local breeding farms between 2016 and 2021. A total of 56,970 (males, 29,530; females, 27,440) Hanwoo calves were classified according to sex or birth and weaning season (March-May, spring; June-August, summer; September-November, fall; and December-February, winter). The birth weight of Hanwoo calves differed according to the birth season. As such, birth weight of the summer-born calves was the lowest. Additionally, the 90-day weaning weight was positively correlated with birth weight. Interestingly, however, the 90-day weaning weight was not related to the birth season but was related to the 2-month seasonal effect during the lactation period. Furthermore, the 90-day weaning weight was the lowest during the summer lactation period. In the beef cattle industry, daily weight gain is an important economic characteristic related to feed efficiency and growth. Our findings will contribute the management of Hanwoo cattle and analysis of changes in economic characteristics due to high temperatures.

• Journal of Preventive Medicine and Public Health
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• v.49 no.2
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• pp.134-138
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• 2016

Objectives: Season of birth, an exogenous indicator of early life environment, has been related to higher risk of adverse psychiatric outcomes but the findings for Alzheimer's disease (AD) have been inconsistent. We investigated whether the month or season of birth are associated with AD. Methods: A nationwide nested case-control study including all community-dwellers with clinically verified AD diagnosed in 2005 to 2012 (n=70 719) and up to four age- sex- and region of residence-matched controls (n=282 862) residing in Finland. Associations between month and season of birth and AD were studied with conditional logistic regression. Results: Month of birth was not associated with AD (p=0.09). No strong associations were observed with season (p=0.13), although in comparison to winter births (December-February) summer births (June-August) were associated with higher odds of AD (odds ratio, 1.03; 95% confidence interval, 1.00 to 1.05). However, the absolute difference in prevalence in winter births was only 0.5% (prevalence of those born in winter were 31.7% and 32.2% for cases and controls, respectively). Conclusions: Although our findings do not support the hypothesis that season of birth is related to AD/dementia risk, they do not invalidate the developmental origins of health and disease hypothesis in late-life cognition. It is possible that season does not adequately capture the early life circumstances, or that other (postnatal) risk factors such as lifestyle or socioeconomic factors overrule the impact of prenatal and perinatal factors.

• Journal of Animal Science and Technology
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• v.63 no.4
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• pp.759-765
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• 2021

Recently, summer temperatures have frequently been abnormal in Korea owing to global warming. In summer, a decrease in feed intake rate and biological activity were observed in Hanwoo (Korean Native Cattle), leading to lower production rates in the industry. However, the precise scale of damage was not reported as with other animals of economic value. This study was conducted to investigate the effects of birth season on birth weight in Hanwoo. Data were collected from 100 local breeding farms from 2016 to 2019. A total of 41,081 Hanwoo calves were classified and analyzed by sex, year, month, and season (March-May, spring; June-August, summer; September-November, fall; and December-February, winter) of birth. The birth weight of Hanwoo calves differed according to birth month. The average birth weight of male calves was 30.47 kg and that of female calves was 28.16 kg. Hanwoo birth weight was the highest in March-born calves and the lowest in July-born calves. The birth weights of calves born in February, March, April, November, and December were significantly larger than those of calves born in July. In addition, the birth weight of Hanwoo calves from the summer was significantly lower than that of calves born in other seasons. Furthermore, Hanwoo steer slaughter age showed a negative correlation, whereas carcass weight had a positive correlation with birth weight. In the beef cattle industry, birth weight is a very important economic characteristic that is related to growth rate. These data will contribute toward planning the reproduction of Hanwoo and analysis of changes in characteristics of economic value owing to high temperatures.

• Korean Journal of Veterinary Service
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• v.46 no.2
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• pp.147-156
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• 2023

Between February 2020 and September 2021, a total of 452 dairy calves with diarrhea were investigated across 17 dairy farms in Gyeonggi province, Korea, using a rapid diagnostic kit. The study aimed to examine the infection rates of major pathogens causing diarrhea in dairy calves, categorizing them by season, age, and birth month. Additionally, logistic regression analysis was conducted to investigate the factors affecting the infection rate. The infection rates of the major pathogens causing infectious diarrhea in dairy calves, including bovine rotavirus, bovine coronavirus, Cryptosporidium, and E. coli, are influenced by season, age, and birth month. Bovine coronavirus and Cryptosporidium showed variations in infection rates according to season, age, and birth month, while bovine coronavirus was influenced by age and birth month, and E. coli showed variations in infection rates based on age. Furthermore, in the analysis of risk factors influencing the infection rates of these pathogens, age and birth month were identified as risk factors for bovine rotavirus, bovine coronavirus, and Cryptosporidium.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.672-678
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• 2006

The objective of this study was to investigate whether milk performance is impacted by the housing of heifers from the second to the seventh day of life, the method of feeding milk from the second week of life to weaning, the sire lineage and by the season of birth and season of calving. From 32 Holstein heifer-calves, which spent their first day of life in a loose housing maternity pen with their mother, 19 heifers were randomly placed in hutches (IH), and 13 stayed in a loose housing maternity pen (MP). At the seventh day IH heifers were assigned to one of two treatments, 10 heifers were randomly taken from IH and relocated to a loose housing pen with an automatic feeding station (AD), 9 calves stayed in hutches with bucket drinking (BD). MP heifers were moved to a group pen with nursing cows (UD). All animals were weaned at the age of 8 weeks (56 days) and kept in group pens. After calving, they were in free-stall housing. Trial cows were divided according to the sire, season of birth and calving. The five-factorial ANOVA revealed that among all the factors taken into account in this study, only sire lineage and season of birth had significant effects. The production of milk, FCM and protein were higher in the MP group than in the IH group. The UD group tended to have the highest production of milk, FCM, protein, lactose, SNF and total solids (TS) and the AD group the lowest. The content of fat and TS were highest in the AD group. Effects of the sire were significant for average daily gains (ADG) from birth to weaning ($0.55{\pm}0.03kg$, p<0.05), contents of fat ($3.81{\pm}0.08%$, p<0.05), protein ($3.13{\pm}0.02%$, p<0.05), and TS ($12.67{\pm}0.12%$, p<0.05). In the season of birth evaluation, statistical difference was found only in the content of protein ($3.13{\pm}0.13%$, p<0.05). Cows born in March-May had the highest % protein and cows born in June-August the lowest ($3.21{\pm}0.04$ vs. $3.06{\pm}0.05%$). Dairy cows born and subsequently calving in December-February had the highest production of milk, protein and TS, and dairy cows born in June-August the lowest. FCM and fat yields were highest in the group born in September-November and lowest in the group born in June-August.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.4 no.1
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• pp.46-53
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• 1993

To find some involvement of environmental factors in autism, season of birth, birth order, and maternal age at birth of autistic children were investigated Total number of clinical outpatient autistic children was 357, which consisted of 319 male and 38 female, then male-to-female sex ratio was 8.4 to 1, and all subjects were born during $1986{\sim}1988.$ These data were compared with those of controlled general populations. The results were as follows : 1) In monthly and seasonal distributions of birth, autistic children were not different from normal control 2) Comparing with control group by Slater's and Greenwood-Yule's birth order calculation methods, there was no significant difference in birth order of autistic children 3) The maternal ages at birth in autistic group were significantly higher than those of control group(P<01) 4) High-risk pregnancies were significantly frequent in autistic group compared with control group(p<01)Our study supported the idea that at least some environmental factors, especially at-risk pregnancy, are involved in autism causation.

• Clinical and Experimental Pediatrics
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• v.59 no.5
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• pp.218-225
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• 2016

Purpose: The recent increase in the prevalence of allergic diseases is hypothetically attributed to immune dysregulation in turn caused by a reduction in exposure to sunlight. We explored relationships between birth season, sunlight exposure, exercise duration, and an allergic disease. Methods: We performed a questionnaire-based survey on allergic diseases among elementary school students. Birth time was categorized according to the season (summer and winter). Results: The prevalence of atopic dermatitis (AD) "symptoms ever" was higher in the children born in winter than in those born in summer (adjusted odds ratio [aOR], 1.24; 95% confidence interval [CI], 1.03-1.49; P=0.024). Birth in winter was associated with an increase in the "symptoms in the past 12 months" prevalence of food allergy (FA) (aOR, 1.56; 95% CI, 1.09-2.24; P=0.015). The lifetime prevalence of allergic diseases except FA was higher in the children whose parents considered their sunlight exposure prior to 24 months of ageas inadequate than those who considered their exposure as adequate ("diagnosis ever" asthma: aOR, 1.4; 95% CI, 1.17-1.67; P<0.001; allergic rhinitis [AR]: aOR, 1.4; 95% CI, 1.17-1.67; P<0.001; AD: aOR, 1.26; 95% CI, 1.06-1.51; P=0.01). Neither recent sunlight exposure nor exercise duration was associated with the prevalence of an allergic disease. Conclusion: Birth in winter may be associated with development of AD and FA. Inadequate sunlight exposure before the age of 24 months might possibly increase the risks of development of asthma, AR, and AD.

• Journal of Embryo Transfer
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• v.8 no.2
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• pp.97-103
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• 1993

This study was conducted to determine the main effects of the parity and farrowing season on gestation length and newborn pigs on the basis of the data obtained from 234 litters of Landrace breeds raised at an integrated swine farm in Kyunggy province from January 1991 to December 1992. The results obtained are summarized as follows ; 1. The average gestation length was 115.37 days, and 114.64 days of 8th parity and over was shorter than those of other parities. 2. The averages of litter size and litter size alive per sow were 9.91 and 9.50 heads. The litter size horn at 1st parity was smaller than at other parities, and the litter size in spring was larger than in summer, autumn or winter. 3. The averages of birth weight per litter and pig were 13.53 kg and 1.37 kg. The effect of farrowing season for each litter weight(p<0.01) and pig weight(p<0.05) at birth was significantly higher in spring than other seasons. 4. Incidence of malformation and stillbirth at birth was 4. 10%, and it at 8th parity and over showed the highest rate(7.50%).

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.3
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• pp.313-317
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• 1997

Data collected from crossbred dairy cattle at the Institut Haiwan, Kluang, were used to evaluate the effects of breed of sire, percentage of Bos taurus inheritance and season of birth on some calving traits. Breed of sire effect was significant on age at first service (p < 0.01), age at first calving (p < 0.01) and postpartum interval to first service (p < 0.05) but not on calving interval (p > 0.05). Linear contrasts indicate that crossbred-sired cows had first service 593 days earlier and first calving 508 days earlier than purebred-sired cows. Cows sired by Friesians, however, had the earliest first service (466 days) and were among the earliest at first calving (917 days). However, the crossbred-sired cows had slightly longer post-partum interval to first service (13 days longer) and calving interval (20 days longer). Percentage of B. taurus inheritance affected (p < 0.01) all the calving traits studied. In general, the cows with 50% inheritance had the best calving performance. Season of birth had no effect (p > 0.05) on them.

• Korean Journal of Veterinary Service
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• v.46 no.1
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• pp.47-58
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• 2023

Between February 2020 and September 2021, 378 calves with diarrhea were investigated across 96 cattle breeding farms in Korea, using a rapid diagnostic kit. The study examined the infection rates of major pathogens causing diarrhea in calves, which were categorized by season, age, birth month, and region. Additionally, logistic regression analysis was conducted to investigate the factors affecting the infection rate. The study found that the five representative pathogens causing calf diarrhea exhibited differences in infection rates based on season, region, age, and birth month. Bovine rotavirus, bovine coronavirus, Cryptosporidium, and Giardia commonly exhibited varying risks of infection based on season and age. Furthermore, in addition to these risk factors, bovine rotavirus and Cryptosporidium were found to impact the infection risk of each pathogen by region, while Giardia was found to be affected by birth month.